The Big Delta is a giant 3-D printer big enough to print buildings. It is, says WASP, the Italian company behind it, the biggest 3-D printer in the world, and it is designed to build homes in developing countries.

WASP makes smaller printers with essentially the same design. They’re cabinets with three arms that run up and down the three edges of the box. By moving the three arms to different heights, the print head that joins the three arms together can also be moved horizontally. The head itself is an extruder made to push out clay. Once set in motion, the printer builds up a ceramic structure with a continuously-laid bead.

The Big Delta works in the exact same way, only its structure is an open matrix of steel gantries. It looks a lot like a cross between an outdoor music stage and the skeleton of a gasometer. This hexagonal structure lets the oversized print head run anywhere inside. This video, from a demonstration in November 2014, shows a smaller version of the same giant printer:

The idea is that the superstructure can be erected anywhere, and its hopper filled up with locally-sourced materials—clay for example. Then the printer goes to work, building an entire dwelling with no human help needed other than keeping the printer’s clay reservoir topped up.

The Big Delta was demonstrated at a three-day event in Massa Lombarda, Italy. “We demonstrated that ours was not just a dream, that low cost housing is possible and that it houses can be built with a 3D printer,” said WASP’s creator Massimo Moretti at the event. “We also developed a model for sustainability.”

That model continues to the company itself. The sale of smaller 3-D printers is generating around $2.2 million per year, which the company says it reinvests entirely in research.

Low cost, high-quality housing is just the beginning. WASP is working with another Italian company, Health R&S, to 3-D print houses which have insect-repelling walls. This project, says Health R&S’s Giorgio Noera, is “not far from completion,” and will be “of fundamental importance in areas where civil population needs to fight infection in order to survive.”

There’s some irony that the developing world gets 3-D-printed, insect-proof housing, while we in the developed world continue with old-fashioned construction and mosquito-friendly dwellings.